Jules Verne's book Journey to the Center of the Earth is about Professor Otto Lidenbrock's discovery of a map with directions to the center of the earth and his subsequent journey there.
Otto decides to try to get there with the help of his nephew Axel and a guide named Hans. The map leads them into a dormant volcano. The central problem is that the volcano is a dangerous place full of obstacles as they attempt to reach the earth's center. For instance, they encounter prehistoric creatures and dangerous flammable gas. They also end up in several perilous situations, like almost dying of thirst and getting separated from one another. For a while, they are able to navigate the volcano's challenges, but they eventually find their path blocked by a rockslide. The only way they can think to move it is by using dynamite, which causes an eruption, and they are ejected out.
In the end, the three of them become famous, but the volcano remains a barrier to reaching the center of the earth. However, recall what Otto says to his nephew:
Science, great, mighty and in the end unerring, science has fallen into many errors—errors which have been fortunate and useful rather than otherwise, for they have been the steppingstones to truth.
This quote reminds readers that even when mistakes are made in scientific experiments and even when problems arise, they are all learning experiences that will one day lead to the true answer. This lesson can be applied to the explorers' journey: though they faced many obstacles and ultimately did not reach their intended destination, they learned a great deal.